The disclosure relates to a hydraulic pump assembly for a hydraulic vehicle brake system. It is used to build up pressure during a slip control operation or, alternatively, for a power braking operation and for returning brake fluid from wheel brakes during or after a slip control operation. Slip control systems include antilock control systems, traction control systems and/or electronic stability control systems, the latter also being referred to in common parlance as antiskid control systems. Common abbreviations for such control systems are ABS, ASR, FDR and ESP. Moreover, the disclosure relates to a hydraulic vehicle brake system with a hydraulic pump assembly of this kind and to a production method or centering of a rotor in a stator of an electric motor of the hydraulic pump assembly.
Piston pumps having one pump element for each brake circuit, in the typical case of two brake circuits therefore one piston pump with two pump elements, are nowadays conventional in slip-controlled hydraulic vehicle brake systems. The pump elements are arranged coaxially in a horizontally opposed arrangement on both sides of an eccentric arranged between them. The eccentric can be driven in rotation by means of an electric motor and the axis thereof is radial with respect to the pump elements. Pump pistons rest by means of mutually facing ends on the outside circumference of the eccentric and, during a rotary motion of the eccentric, are driven to perform a reciprocating motion, by means of which they deliver brake fluid in a manner known per se.